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To repair eight deteriorating chimneys atop the historic Pioneer Courthouse in downtown Portland, Pioneer Waterproofing had to dig up some suitable materials.

National Trust for Historic Preservation standards required that the materials match those on the 139-year-old building. That was a problem because the Washington quarry that had produced the chimneys’ sandstone didn’t have any more available, said Michael Crawford, owner of Pioneer Waterproofing.

The courthouse, designated a National Historic Landmark in 1977, has received restoration work in several phases; Crawford is hoping this will be the last of it for a while.

鈥淭hey had tried to repair those (chimneys) before, but the stone continued to deteriorate 鈥� (and) continued to crack,鈥� he said. 鈥淚t just got to a point where it’s better to replace the stone because it’s gotten so bad.鈥�

Pioneer Waterproofing benefited from Crawford’s connection with Toronto-based Old World Stone, which had in Nova Scotia a supply of sandstone that matched the courthouse’s stone.

Approximately 75 tons of stone will be trucked in from Canada and then hoisted and put into place atop the courthouse starting in September. The stone weighs 145 pounds per cubic foot, with side stones weighing 400 pounds apiece and cap pieces for the chimney decks weighing upwards of 2,000 pounds each, Crawford said.

鈥淗istoric jobs tend to be unique and they bring different challenges,鈥� he said. 鈥淚 don’t know if I will ever do another one like it.鈥�

Pioneer Waterproofing also is replacing defective mortar joints and patching areas from the second floor to the ground floor on the building’s north and east sides. Other sides were repaired during previous phases. The firm is hoping to finish its work by January.